NAV 3 Flashcards
(139 cards)
1
Q
What are the six key pilot responsibilities of a pilot in reference to flight planning
A
Route
Alternative aerodromes
Weather (at all stages)
NOTAM’s
Aerodrome facilities
Safe levels to fly
2
Q
What are three consequences of poor pilot navigation
A
CFIT
Fuel starvation
Airspace infringement
3
Q
What frequency bands do NDB’s typically operate in
A
LF & MF
4
Q
How can a pilot know if they are referring to the correct NDB
A
NDB transmits unique alphabetical morse code
5
Q
What are the advantages of an NDB
A
Cheap to install and maintain
Most instrument procedures can be designed to use an NDB
6
Q
What on an aircraft is used to make use of an NDB
A
Automatic direction finder (ADF)
7
Q
What direction is a VOR orientated and how many radials does it have
A
Orientated north, 360 radials
8
Q
How does a VOR function
A
Send first a non-directional reference signal then a rotating variable signal with the aircraft comparing the two to find the radial
9
Q
What frequency band does a VOR operate on
A
VHF, typically 108MHz - 117.975MHz
10
Q
How can a pilot know they are using their intended VOR
A
VOR transmits at least every 30 seconds its alphabetical morse code, 2 or 3 letters long
11
Q
What are some drawbacks of VOR vs NDB
A
VOR requires more space, more expensive & as VHF needs line of sight
12
Q
At what phase of flight is a VOR typically used
A
En-route navigation (high & low level), also as an approach aid
13
Q
What is the typical range of a VOR
A
200nm
14
Q
How can VORs be used to create a route
A
Establish waypoints at the intersections of 2 VOR radials
15
Q
In basic terms how does a DME function
A
Aircraft transmits interrogation pulse and times the gap to the reply pulse to find distance
16
Q
Where a VOR & DME are collocated what can an aircraft determine regarding its position
A
Its radial and distance to the station
17
Q
How can a pilot be sure they are tuned to the correct ILS
A
Unique morse code identifier
18
Q
What three pieces of information does an ILS system provide to a pilot
A
Glidepath
Localiser
Distance information
19
Q
What two signal beams does an ILS system broadcast
A
Right/below of pilots view 150Hz blue sector
Left/above of pilot view 90Hz yellow sector
20
Q
What are the standard positions of the glide path and localiser in reference to the runway (meters)
A
Localiser 300m beyond runway
Glidepath 300m beyond runway threshold, 120m to side of runway centreline
21
Q
What is a typical approach glide path
A
2.5° to 3°. Above 4.5° steep approach, need approved aircraft
22
Q
What is the typical range of an ILS glide path and localiser in nm
A
Glidepath 10nm
Localiser 25nm
23
Q
In nav what can VDF be understood to mean
A
VHF Direction Finder
24
Q
What signal is VHF direction finding equipment looking for
A
Typically the specific frequency the aircraft is communicating on
25
In simple terms how does VDF equipment function
Ring of antenna receiving signal at slightly different times hence can ascertain direction of the transmission is coming from
26
In nav what is TACAN
Mil variant of VOR & DME equipment. More accurate than civil as uses UHF
27
What equipment does an a/c use to interpret an NDB signal
Automatic direction finder (ADF)
28
How could an NDB be used as part of an aircraft approaching an aerodrome
Used as a locator to find the start are of an ILS approach or a path to follow for the arrival procedure
29
What equipment can be used to create a virtual reporting point where no navaid exists
VOR, a point where two radials intersect
30
What is the use of an NDB
Non-Directional beacon. Non-precision navigation
31
What is the use of a VOR
VHF Omni-directional range. En-route and approach aid. 360 ° radio signals
32
What is the used of DME
Distance measuring equipment. Distance info of the slant range
33
What is the use of ILS
Instrument landing system. Precision approaches
34
What is the use of VDF. What two pieces of information does it give
VHF Direction finder.
Gives QDM, magnetic bearing aircraft should fly to get to VDF station.
QDR, magnetic bearing aircraft is from the station
35
What is the use of TACAN
Tactical air navigation system. UHF Mil system for en route nav & non-precision approach. VOR/DME system
36
What is RNAV
Random Navigation, Rather than navigating point to point instead navigate between navaids by using their relative distance
37
How can RNAV be used without any ground navaids at all
Inertial navigation systems and satellite
38
In navigation what is homing
Keeping the nose of the aircraft to the navaid, can cause a curve in the path if there is a crosswind
39
When an aircraft is navigating to and from an NDB, how does homing differ from inbound/outbound tracking
Homing is always pointing at the beacon. Inbound/outbound tracking is navigating to and from a beacon while accounting for the wind to give a direct track
40
In navigation what are IAPs
Instrument approach procedures. Allows a pilot to conduct an instrument approach with little ATC instruction
41
What are some navigation systems that can be used to establish holds
VOR, NDB, Radial/DME fix, specified waypoint, visual reporting point
42
How long does a typical hold take
4 minutes, 1 min for each leg and each 180 degree turn
43
What chart details the approach for an aerodrome
Standard arrival chart (STAR)
44
How accurate is an NDB
+/- 5°
45
How does the range of en-route and aerodrome NDBs differ
En-route are more powerful
46
What can be added to a TACAN to allow civil use
VOR, becomes a VORTAC
47
What six limitations of an NDB are there
Lightning, audible on receiver
Two NDB stations on same frequency
Wave interference at night
Signal refracted at the coast
Signal reflected off mountain hence duplicated
Quadrantal error, signal distorted by airframe. 045°, 135°, 225°, 315° Worst
48
How accurate is a VOR in degrees
+/- 2° but practically better than that
49
What are the limitations of a VOR
Cone of confusion directly above it
Must be located without line of sight being blocked
Adjacent navaid frequency interference
Occupy large area, expensive to maintain
50
What is the accuracy of a DME
+/- 0.1 NM if using the slant range
51
What are the limitations of DME
Slant range, worse for high a/c close to DME
May drop out over top of DME
Requires line of sight
Cane be overwhelmed when 100+ a/c interrogating
52
What three categories of ILS are there
1, 2, 3 (A,B,C)
53
What is the most and least accurate category of ILS
Most 3C
Least 1
54
What happens to ILS accuracy as the aircraft gets closer
Gets more accurate
55
What are the limitations of ILS
Critical area, vehicles & aircraft interfering if near antenna
Siting, first 200m must be over flat surface
Weather, snow and heavy rain weaken signal
A/c & crew, need trained pilots and a/c equipment to use most accurate categories
Radio, FM below 108MHz could interfere
56
What is the accuracy and range of VDF equipment
+/- 2°
200 NM
57
What are the limitations of VDF
Height of transmitter & receiver in relation to the terrain affect range
Have to been communicating on freq to get a measurement
58
What is the accuracy and range of TACAN
+/- 1° often better
200NM
Still works in snow, sand storm, rain, humidity
59
What are the limitations of TACAN
Requires line of sight but less of an issue as UHF
Still has slant error as a form of DME
Only can be used by mil unless VORTAC
60
What three basic component parts are there in an internal navigation system (INS)
Accelerometers (3)
Gyroscopes (3)
Computer to interpret
61
How does the INS system integrate with ground based navaids
Doesn't need ground navaids to operate but useful to recalibrate on route
62
What are the limitations of an INS in nav
Accuracy degrades 0.6nm per hr
Minor gyro and accel errors introduces large errors
Requires correct lat & log at start
63
In nav how does an INS and IRS differ
INS, inertial navigation system. IRS inertial reference system. IRS uses lasers, frequency difference in two lasers
64
In nav what are the benefits of an IRS over an INS
IRS can be updated by GNSS so no user input error
Can operate standalone is GNSS issues
Easier to maintain
More accurate than INS
65
For an INS, what is meant by lock-in
Slow rotation cause laser frequencies to get very similar. Can be countered by forcing rotation
66
What can an INS/IRS system be used to measure
Pitch, roll, yaw
True & magnetic heading
True air and ground speed
Wind speed, direction & drift
Vertical climb and decent
67
What natural phenomena does an INS/IRS system take into account
Earth rotation & Coriolis effect
68
How many and at what altitude makes up a typical GNSS constellation
24-36
20000km
69
What four components makes up a satellite
Atomic clock
Transmitter
Receiver
Solar panels
70
In a GNSS system, when the signal of 4 satellites is received what can be calculated in addition to lat & log
Altitude
71
What four factors are GNSS systems assessed along
Accuracy
Integrity
Continuity
Availability
72
In GNSS what is an aircraft based augmentation system (ABAS)
Using onboard integrate and augment GNSS signals. Judging if a signal is erroneous by comparing it to the others (RAIM). Evaluating it against internal system like INS & altimeter (AAIM)
73
In GNSS what is an satellite based augmentation system (SBAS)
Gather satellite data continent wide, check and correct if needed. Augmented data sent to aircraft who use it over the original
74
In GNSS what is an ground based augmentation system (GBAS)
Supports final approach primarily, critical flight stage. Quick alert from ground system signal isn't accurate
75
What are the benefits in nav of multi-constellation, multi-frequency system
Multiple constellations means signals can be compared to correct for ionospheric errors. More accurate, obtain location quicker, less impact of obstructions like buildings, less impact of global outage
76
What are some limitations of satellite based systems
Sometimes can't see them
Satellites too close causing dilution of precision
Multi-path reflection off hills or atmosphere triggering wind warnings
Airframe shadows signal
Terrain shadowing
Solar flares, v hard to predict
Interference & jamming
Governments can turn them off
77
What are the three instrument approach types using aeronautical charts
Precision approach (PA)
Procedure with vertical guidance (APV)
Non-precision approach (NPA)
78
On an approach chart, what information is shown to signify it is a precision approach (PA)
ILS
79
On an approach chart, what information is shown to signify it is a procedure with vertical guidance (APV)
RNAV (GNSS)
80
On an approach chart, what information is shown to signify it is a non-precision approach (NPA)
VOR/DME
81
What are some features of a precision approach
Lateral and vertical guidance, 3D approach
Still need visual reference with runway at a set altitude (decision height) Better ILS category, lower decision height
82
What affects what ILS category a pilot can fly
Aircraft equipment
Ground equipment
Pilot qualifications
83
What are some features of a non-precision approach
Lateral but **no** vertical guidance. 2D
At the end of the approach pilot must have visual of runway to decide if to land
Minimum descent altitude/height for QNH/QFE
84
In approaches how does Decision altitude/height and minimum descent altitude/height differ
Decision = precision
Minimum = non-precision
85
What is the name for the measurement on a chart that dictates the lowest level an aircraft can descent without visual reference to the surfact
Obstacle Clearance Altitude (OCA)
86
What is the visual manoeuvring element of an obstacle clearance altitude
The lowest height an aircraft can descend without visual reference to the surface. Using the ILS for a different runway then circling for the runway they actually want to use
87
What do the different category's on an instrument approach chart mean
Different minima for different types of aircraft. Bigger aircraft going faster have to decide higher off the ground
88
What is visual manoeuvring (circling) in an approach
After completing an instrument approach, allows a/c to reposition with visual reference to the ground for another runway
89
On an approach chart what is a typical category A aircraft, how fast is it flying
Small single engine 70-90kts
90
On an approach chart what is a typical category B aircraft, how fast is it flying
Small multiengine 85-130kts
91
On an approach chart what is a typical category C aircraft, how fast is it flying
Commercial jet 115-160kts
92
On an approach chart what is a typical category D aircraft, how fast is it flying
Large commercial jet 130-185kts
93
What measurement indicates the minimum altitude/height an aircraft can descend to and remain clear of obstacles & terrain
Obstacle clearance altitude (OCA)/ Obstacle clearance height (OCH)
94
What is obstacle clearance altitude (OCA)
Lowest altitude with reference to mean sea level to comply with obstacle clearance criteria
95
What is obstacle clearance height (OCH)
Lowest height with reference to runway threshold of aerodrome elevation to comply with obstacle clearance criteria.
Precision - Threshold
Non precision - Aerodrome elevation (or threshold if it is greater than 7ft below aerodrome elevation)
96
What is minimum descent altitude (MDA)
Minimum altitude in reference to mean sea level for non-precision approach or circling approach. Must not go below without seeing the runway
97
What is minimum decent height (MDH)
Minimum height for non precision or circling approach in reference to aerodrome elevation or threshold if more than 7ft below aerodrome elevation. Must not go below without seeing the runway
98
What is decision altitude/height (DA/DH)
Specified altitude or height on an instrument approach where runway/lights must be seen, past which a missed approach must be executed
DA - Mean sea level
DH - Threshold elevation
99
In instrument approach fixes what is an IAF
Initial approach fix, separate en-route from approach
100
In instrument approach fixes what is an IF
Intermediate approach fix, start of the intermediate segment
101
In instrument approach fixes what is an FAF/FAP and how do they differe
Final approach fix for non-precision or Final approach point for precision approach. Begin of the final approach segment. Alignment and descent for landing accomplished
102
In instrument approach fixes what is an MAPt
Missed approach point. If visual references not achieved a go around must be executed. The missed approach phase provides obstacle clearance
103
How does conventional and area navigation differ
Conventional flying point to point to ground navaids. Aera navigation (RNAV) allows flying between the waypoint by referencing distance and bearing to each
104
What is area navigation another name for
RNAV
105
What are the benefits of RNAV
More direct routing that can be quicker and more fuel efficient hence making more efficient use of the airspace
106
In an RNAV system what is path definition error
When the path defined by the RNAV system is different from the desired path
107
In an RNAV system what is defined path
The route the navigation system decides as the desired path
108
In an RNAV system what is flight technical error
Error from how close the pilot/autopilot is able to follow the desired path
109
In an RNAV system what is navigational system error
Difference between where the a/c nav system estimates its position to be and its true position
110
In an RNAV system what is total system error
The combination of path definition error, flight technical error and navigation system error
111
What are the four recognised RNAV accuracy specifications
RNAV 10 95% of the time within 10 miles of the defined path
RNAV 5
RNAV 2
RNAV 1 95% of the time within 1 mile of the defined path. Called P-Nav
112
In RNAV how are waypoints defined
5 letter geographical position at a set distance/baring from a navaid or a lat/long coordinate
113
In what two ways may an a/c interact with a waypoint
Fly over or fly past
114
In RNAV how does required navigation performance (RNP) build on the principle
Aircraft systems monitor and alert how accurately an aircraft is flying a route. Some routes may have requirements of how accurate an a/c can report its route relative to the RNAV route
115
If an a/c has sufficient required navigation performance is enables RF legs. What is this?
Following a set curved path typically on approach with a defined start and finish
116
If an a/c has sufficient required navigation performance is enables FRT legs. What is this?
Used in en-route flight, allowing curved route around a fixed point rather than following a series of waypoints
117
In RNAV what is an offset flight path
When suitably required navigation performance equipped pilot can offset from the defined route. 1NM increments up to 20NM
118
In navigation what is SLOP
Strategic lateral offset procedure. Seen in north Atlantic traffic, offsetting aircraft 1 or 2 nm to help with wake/aircraft not where they should be & emergencies
119
What technique can be used in navigation to allow an aircraft at the same FL to overtake a slower aircraft
Parallel offset, moving aircraft over to overtake. If route has 5nm accuracy then shift over 7nm
120
On an aircraft what is a FMS
Flight management system
121
On an aircraft was tasks does the FMS take on
Managing onboard navigation systems. Database of navaids, aircraft performance, aerodrome data, SIDs & STARs and airway data
122
How does the FMS help routing systems on an aircraft
Given waypoints it calculates the route and can update the INS with GNSS data
123
A flight management computer has four main components, what are they
Flight management computer (FMS). Navaid database
Automatic flight control system (AFCS)
124
In an aircraft FMS what does the FMC do
Flight management computer
Navaid & aerodrome database
125
In an aircraft FMS what does the AFCS do
Automatic flight control system
Autopilot
126
In an FMS what does the AHRS do
Calculates aircraft position. Uses INS, GNSS & ground navaids
127
In an FMS what does the EFIS do
Displays the data in the cockpit on flight displays (primary & multi). Every detail about the aircraft
128
On an aircraft FMS what is LNAV & VNAV
Lateral and vertical navigation. Give aircraft the waypoint to hit and it can work out best point to turn/ascend/descend
129
In navigation what are the three components of performance based navigation
Specification (a/c performance requirements), infrastructure (ground & space navaids needed) and application (applying the specification & infrastructure to the routes)
130
How does area navigation (RNAV) & required navigation performance (RNP) differ
RNP requires on-board monitoring & alerting of route accuracy performance. Aircraft compares perceived certainty of its location against RNP requirements
131
What three navaids for a part of the RNAV structure hence enabling performance based navigation (PBN)
VOR
DME
GNSS
132
What are the benefits of performance based navigation (PBN)
1. Reduced maintenance costs for ground navaids
2. Reduced needs to develop more advance ground navaids
3. More efficient airspace use. Less fuel burn, less noise, less congestion
4. More consistent application of RNAV & RNP globally
5. Airports more accessible in incremental weather
133
What are the accuracy requirements for RNAV
Accurate to the requirements 95% of the time both lat & long. RNP 10 = 10nm RNP 2 = 2nm
134
In Europe how does basic RNAV and precision RNAV differ
Basic is RNAV 5 (mandatory for upper airspace) and precision is RNAV 1 (mandatory for terminal airspace)
135
In Europe what is the RNP accuracy requirements for radius to fix
RNP-1
136
In Europe in what phases is RNP APCH used in navigation
Initial, intermediate, final and missed approach phases. Final approach 0.3nm accuracy 95% of time
137
What aircraft use RNP 0.3 in Europe
Helicopters
138
In nav future developments what is point merge
Pre-defined approach legs merging to a single point that aircraft can be routed towards at any time to give spacing. More efficient, less coms and workload for controller
139
In nav future developments what is free route airspace
A/c can route through defined airspace without being restricted by the ATS structure. Enter & exit at defined points. Reduced flight time, fuel burn hence less CO2 & costs
